JP2011020147A - Dust collecting/discharging apparatus for laser beam machining - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dust collecting/discharging apparatus for laser beam machining that moves in conjunction with the movement of an optical system and that highly accurately discharges dust even if the moving speed of the dust collecting/discharging apparatus is high. <P>SOLUTION: The apparatus includes a dust collection body 30 including: a side wall section 12 that surrounds a laser beam machining part; an upper wall section 11 that hermetically shields an upper opening of the side wall section 12 and that has a window 14 for transmitting a laser beam; and a bottom section 13 that has an opening 16 in a position opposite to the machining part of a planar workpiece 41. The apparatus further includes: a sucking/discharging means that sucks dust from the opening 16 installed in the bottom section 13 of the dust collection body 30 and that discharges dust from a discharge port 15 installed in the side wall section 12 of the dust collection body 30; an air curtain forming means that jets air from the periphery of the opening 16 of the bottom section 13 of the dust collection body 30 and that forms an air curtain 18 in an area between the bottom section 13 and the planar workpiece 41; and an outer peripheral wall 19 that surrounds the air curtain 18. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to fine processing of a large-sized sheet material in processing of a surface of a flat workpiece (sheet material) by laser irradiation, particularly in the production of an optical filter for display or a solar cell module used in a plasma display panel (PDP) or the like. The present invention relates to a dust collector for laser processing used for processing.

  Conventionally, processing of a sheet material by laser irradiation (laser processing) has been performed in the manufacture of a display optical filter, a solar cell module, and the like used in an image display unit of a display such as a PDP or a liquid crystal display panel. For example, in the case of an optical filter for a PDP, a mesh-like conductive layer is usually provided inside the filter in order to shield radiation of unnecessary electromagnetic waves generated from the PDP. Therefore, laser processing is used as means for removing the functional layer on the surface of the filter and exposing the conductive layer (Patent Document 1). In this case, it is required to perform micromachining with extremely high accuracy so as not to damage the conductive layer, to stably remove only the functional layer having a thickness of 10 μm or less, and to prevent the removed resin dust from reattaching.

The drive system of the two-dimensional machining system using laser machining
(1) Workpiece moving method: A method of processing a laser beam to a fixed machining head position, focusing it, and moving the table on which the workpiece (workpiece) is mounted to process it into a desired shape.
(2) Optical movement method (flying optics): A beam mounted at an arbitrary position by fixing a table on which a workpiece is mounted and moving an optical relay point (abbreviated as an optical system) such as a processing head or a reflecting mirror. Method to reach,
(3) Combined method: A method that partially performs light movement and workpiece movement,
There is.

  In general, the workpiece moving method is advantageous for fine processing. Since the optical system does not move, the optical path length is fixed, high processing accuracy can be maintained, and the processing points are fixed, so a dust collection device that eliminates dust and gas generated during processing is also installed centrally. This is because dust can be removed with high accuracy. However, when finely processing large and various types of sheet materials such as the optical filter for PDP as described above, the work moving method not only increases the size of the entire apparatus but also moves a large work. Considering inertia, it is difficult to increase the moving speed. On the other hand, the light movement method can easily scan the work area using a galvano mirror and an F-θ lens processing head if the work is a small work. It is necessary to move the machining head, and it is difficult to increase the moving speed. In addition, even if the beam is propagated by moving a lightweight reflecting mirror, a concentrated dust collection device is installed because the generated dust and gas will spread over a wide range when moved in a free direction at high speed. Can not. In this case, in the dust collection by the conventional blow nozzle and the exhaust duct (Patent Document 2), the generated dust or the like may diffuse and reattach, and it is difficult to eliminate the dust or the like with high accuracy.

  As a countermeasure, an apparatus for moving a machining head equipped with a dust collection device has been developed (Patent Documents 3 and 4). The apparatus of Patent Document 3 has a housing having an opening for allowing a laser beam to pass between a laser beam source and a workpiece, an opening for injecting a pressure gas, and a discharge port connected to a vacuum apparatus. Then, the dust generated on the workpiece is sucked and removed. Further, the apparatus of Patent Document 4 has two cover members having openings for securing an optical path and an air flow path at a lower part of a condenser for irradiating a laser beam to process a workpiece. A dust collection chamber is formed in the introduction chamber and its outer periphery, and air is supplied to the air introduction chamber, and air that generates a swirling flow is supplied to the dust collection chamber. The air ejected toward the workpiece is sucked together with external air in a swirling flow to an exhaust port provided in the dust collection chamber, thereby efficiently removing dust generated on the workpiece.

JP 2008-197539 A JP 2002-035984 A Japanese Patent Laid-Open No. 06-285668 JP 2007-069249 A

  However, the dust collectors described in Patent Documents 3 and 4 have no problem when the moving range is small, the moving speed is low, and the external air flow is not affected, as described above. For large workpieces such as the above, if the moving speed is increased to improve productivity, the flow of external air will affect the airflow due to suction, and it will not be possible to completely eliminate dust, etc. Fine processing may not be possible.

  Accordingly, an object of the present invention is a dust collecting apparatus that removes dust and the like generated from a sheet material, particularly in processing of a flat workpiece (also referred to as a sheet material) by laser processing of a light moving system, An object of the present invention is to provide a dust collecting and discharging apparatus capable of removing dust with high accuracy even when the moving speed of the dust collecting and discharging apparatus moving in conjunction with the movement of the system is high.

The above-mentioned object is a dust collection device that is installed in a processing work space of a laser processing apparatus that processes a flat workpiece by laser light irradiation and prevents dust scattering caused by the processing and discharges dust.
A side wall portion surrounding the laser processing work location, an upper wall portion having a window portion that hermetically shields the upper opening of the side wall portion and allows the laser light to pass therethrough, and a position facing the processing location of the flat plate workpiece A dust collector having a bottom having an opening in the dust collector, and suctioning the dust from an opening provided in the bottom of the dust collector, and discharging the dust from a discharge port provided in a side wall of the dust collector Sucking and discharging means, air curtain forming means for ejecting air from the periphery of the opening at the bottom of the dust collector, and forming an air curtain between the bottom and the flat workpiece, and the air curtain And a dust collecting device for laser processing characterized by comprising an outer peripheral wall surrounding the periphery of the laser beam.

  Thus, by forming the air curtain and the outer peripheral wall surrounding the periphery of the opening (also referred to as the suction port) at the bottom of the dust collector, the vicinity of the processing location of the suction port and the plate-like workpiece is One space can be created. In addition, by making the entrance of the laser beam to the dust collector airtight with a window that allows the laser beam to pass through, the dust collection efficiency of the dust collector is increased and the opening to the outside is limited to the suction port only. Can do. As a result, even if the moving speed of the dust collector becomes high, it can be made less susceptible to the influence of the external air flow, can prevent airflow disturbance due to suction, and can eliminate dust with high accuracy. Can do.

The preferred embodiments of the dust collector for laser processing according to the present invention are as follows.
(1) The air curtain forming means includes a plurality of air ejection holes arranged at predetermined intervals around the bottom opening of the dust collector, and the air is ejected from the air ejection holes by ejecting air. An air curtain is formed.
(2) an inner dust-proof chamber that surrounds the side of the optical path of the laser beam that has passed through the window and is opened at the lower end so that the laser beam passes on the lower surface side of the upper wall of the dust collector; An air feeding means for supplying air into the dustproof chamber in order to make the dustproof chamber have a positive pressure. By providing a dustproof chamber maintained at a positive pressure in the vicinity of the window, dust collected in the dust collector can be prevented from adhering to the window, and the laser light transmittance can be prevented from decreasing. it can. Thereby, it is possible to prevent the processing energy from fluctuating and perform stable and highly accurate laser processing.
(3) The distance from the bottom of the dust collector to the surface position of the flat workpiece is 1 to 3 mm. By setting the clearance between the dust collector and the flat workpiece to the above distance, the space near the machining location is hardly affected by the external air flow, and dust is eliminated with high accuracy. be able to.
(4) The dust collector is provided with eddy current generating means for generating a vortex in the dust collector during the suction operation of the suction / discharge means and discharging the dust from the discharge port as a vortex air flow. It is characterized by that. By generating an eddy current in the dust collection body, it is possible to prevent an anisotropy in the air flow caused by the suction depending on the direction in which the dust collection body moves, resulting in variations in the dust collection performance. Thereby, dust can be eliminated with higher accuracy.
(5) The plurality of air ejection holes are arranged so as to form a substantially circular shape, and the vortex generating means is configured so that each of the plurality of air ejection holes has a predetermined angle in substantially the same direction as the tangential direction of the substantially circular shape. It is characterized by comprising an angle.
(6) The side wall portion of the dust collector is formed in a substantially cylindrical shape, and the eddy current generating means is configured such that a direction in which the dust is discharged from the discharge port of the dust collector by the suction / discharge means is that of the dust collector. It is configured by being set so as to be in the tangential direction of the side wall portion.
(7) A plurality of discharge ports of the dust collector are provided in the side wall portion, and the dust is discharged from the plurality of discharge ports.
(8) The dustproof chamber has a cone shape that gradually decreases in diameter toward the lower end.
(9) The material of the window portion is zinc selenide.

  According to the laser processing dust collecting / collecting apparatus of the present invention, particularly in the light moving type laser processing, the dust collecting device having the function of collecting and discharging dust generated from the sheet material and the suction / discharge means are provided. At the time of laser processing, an air curtain formed by an air curtain forming means and an outer peripheral wall surrounding the air curtain are provided around the suction port at the bottom of the dust collector. The vicinity of the processing location of processing can be made into one space. In addition, since the entrance of the laser beam to the dust collector is hermetically sealed by a window that allows the laser beam to pass through, the dust collection efficiency of the dust collector can be improved and the opening to the outside can be limited to the suction port only. it can. With such a dust collector, even if the speed of movement of the dust collector becomes high, it can be made less susceptible to the influence of the external air flow, so it is possible to prevent airflow turbulence due to suction, Dust can be eliminated with high accuracy.

  Therefore, by using the dust collector for laser processing according to the present invention, dust can be removed with high accuracy even if the moving speed of the optical system is increased when laser processing a large sheet material. Accurate microfabrication can be performed.

It is a schematic sectional drawing for demonstrating a typical example of the dust collection apparatus for laser processing of this invention. It is a figure for demonstrating one example of the suitable aspect of the dust collection apparatus for laser processing of this invention, Fig.2 (a) is a schematic bottom view of the air outlet B vicinity of a dust collector, FIG. b) is a schematic sectional view. It is a figure for demonstrating another example of the suitable aspect of the dust collection apparatus for laser processing of this invention, Fig.3 (a) is a schematic cross-sectional view in the position of the exhaust port of a dust collector, 3 (b) is a schematic perspective view of the dust collector cut in the vertical direction to show the inside. It is a schematic sectional drawing for demonstrating the suitable pressure balance of the inside of a dust collection body at the time of use of the dust collection apparatus for laser processing of this invention.

  Below, the dust collection apparatus for laser processing of this invention is demonstrated, referring drawings. FIG. 1 is a schematic cross-sectional view for explaining a typical example of a dust collector for laser processing according to the present invention.

  As shown in the figure, the dust collector for laser processing according to the present invention transmits laser light 6 propagated from a laser light source by a reflecting mirror or the like (not shown) and condensed by a condenser lens 5 (objective optical element). In a laser processing apparatus that irradiates and processes a processing portion 7 of a sheet material 41 (a plate-like workpiece), it is installed in the processing work space and prevents scattering of dust 42 generated from the processing portion 7 of the sheet material 41 due to processing. It is a dust collection device that collects and discharges to make it. In the present invention, the drive system of the laser processing apparatus is not limited, and any laser processing apparatus can be used. Since the dust collection device of the present invention exhibits highly accurate dust collection performance when moving at high speed, it is particularly useful for light-moving laser processing. In that case, the table 40 on which the sheet material 41 is mounted is fixed, and the optical system including the condenser lens 5 moves to process the sheet material 41.

  The dust collector of the present invention sucks dust 42 that surrounds the laser processing work space between the condenser lens 5 and the sheet material 41 and dust 42 into the dust collector 30 and discharges it from the dust collector 30. A suction exhaust means.

  The dust collector 30 includes an upper wall part 11, a side wall part 12, and a bottom part 13. The side wall 12 of the dust collector 30 has a cylindrical shape surrounding the laser processing space. There is no restriction | limiting in particular in the shape of the side wall part 12, The cross-sectional circular shape, the cross-sectional ellipse shape, and the cylinder shape of a cross-sectional rectangle shape may be sufficient. Considering the operability and the eddy current generating means described later, a substantially cylindrical shape with a circular cross section is preferable. The upper wall portion 11 seals the upper opening of the side wall portion 12, and the bottom portion 13 sucks dust 42 generated at the processing location 7 by irradiation with the laser beam 6 at a position facing the processing location 7 of the sheet material 41. An opening (suction port 16) is provided.

The upper wall portion 11 of the dust collector 30 is provided with a window portion 14 that allows the laser beam 6 to pass therethrough and has airtightness. Although the window part 14 may exist in any position of the upper wall part 11, the center part of the upper wall part 11 is preferable when operativity and the eddy current generation means mentioned later are considered. The material of the window part 14 should just be what can permeate | transmit the laser beam 6. FIG. Generally, the material used for the lens of a laser processing apparatus can be used. Depending on the type of laser light source, in the case of a CO ₂ laser, zinc selenide (ZnSe) or gallium arsenide (GaAs) can be used. Zinc selenide is preferred because of its high transmittance. In addition, when the laser light source is a YAG laser, crown glass, fused silica, or the like can be used. When the laser is an LD laser, crown glass, synthetic quartz, or the like can be used. When an excimer laser is used, synthetic quartz or the like can be used.

  The side wall 12 of the dust collector 30 is provided with an exhaust port 15 as a suction discharge means for discharging dust sucked into the dust collector 30 from the suction port 16 of the bottom 13. The exhaust port 15 is connected to a suction exhaust device (not shown) such as an exhaust blower, and the dust 42 is discharged from the dust collector 30. In general, the discharged dust 42 is collected by a bag filter or the like. The exhaust port 15 may be provided at any position, and a plurality of the exhaust ports 15 may be provided. Usually, it is provided in the vicinity of an intermediate point in the height direction of the side wall 12 as shown in FIG. The shape of the exhaust port 15 is not particularly limited, and may be a circular cross section, an elliptical cross section, or a rectangular cross section. A cross-sectional circular shape in which the airflow in the vicinity of the exhaust port 15 is stable is preferable.

  The suction port 16 provided at the bottom 13 of the dust collector 30 needs to allow the laser light 6 to pass through. Therefore, the suction port 16 may be located at any position on the bottom 13 as long as it is located on the optical path of the laser light 6. . Considering the operability and the eddy current generating means described later, the center of the bottom 13 is preferable. The shape of the suction port 16 is not particularly limited, and may be a circular cross section, an elliptical cross section, or a rectangular cross section. A cross-sectional circular shape in which the airflow in the vicinity of the suction port 16 is stable is preferable.

  In addition, the bottom 13 of the dust collector 30 is provided with air curtain forming means for ejecting air from the periphery of the suction port 16 and forming the air curtain 18 between the bottom 13 and the sheet material 41. As a result, the area from the suction port 16 to the sheet material 41 in the vertical direction can be surrounded by the air curtain 18. Any air curtain forming means may be used, but generally, air is blown from the periphery of the suction port 16 toward the sheet material 41 by an air supply means such as a compressed air supply device.

  A preferred air curtain forming means is configured as shown in FIG. In other words, a plurality of air ejection holes 17 are arranged around the suction port 16 below the bottom 13 so as to inject air toward the sheet material 41 at a predetermined interval. The air curtain 18 that surrounds the region from the suction port 16 to the sheet material 41 in the vertical direction can be formed by the air ejected from the air ejection hole 17. There is no restriction | limiting in particular in the number of the air ejection holes 17, and it should just be arrange | positioned by the space | interval which can form the air curtain 18. As shown in FIG.

  Further, the bottom 13 of the dust collector 30 is provided with an outer peripheral wall 19 that surrounds the periphery of the air curtain 18. Although the outer peripheral wall 19 may be formed of another cover member, it is preferable that the outer peripheral wall 19 is formed of a member constituting the bottom portion 13 in order to have a simple configuration. For example, as shown in FIG. 1, the area including the suction port 16 on the lower side of the bottom portion 13 and the air ejection hole 17 has a shape that is recessed from the bottom surface position of the dust collector 30, so that the surface with the suction port 16 is provided. A projecting outer peripheral wall 19 is formed so as to surround the air curtain 18.

  The height of the outer peripheral wall 19 is not particularly limited. If the air curtain 18 is too low, the air curtain 18 cannot be sufficiently surrounded. If the air curtain 18 is too high, the air curtain 18 does not reach the sheet material 41 or the dust 42 is hardly sucked from the suction port 16. 30 mm, preferably 5 to 10 mm.

  As described above, the dust collector 30 of the dust collector of the present invention surrounds the air curtain 18 that surrounds the area from the suction port 16 to the sheet material 41 in the vertical direction, and further surrounds the periphery of the air curtain 18. By forming the outer peripheral wall 19 to be formed, the vicinity of the processing portion 7 of the sheet material 41 from the suction port 16 is made into one space (referred to as processing space). Further, by making the inlet of the laser beam 6 to the dust collector 30 airtight, the dust collection efficiency of the dust collector 30 is enhanced and the opening to the outside is limited to the suction port 16. Thereby, since it can be made hard to be influenced by the flow of the external air, the dust collector even when the dust collector 30 is moved together with the condenser lens 5 on the large sheet material 41 at high speed. The disturbance of the airflow due to the suction inside 30 can be prevented, and the dust generated at the processing location 7 of the sheet material 41 can be eliminated with high accuracy.

  In addition, as shown in FIG. 1, the dust collection and discharge apparatus of the present invention further surrounds the side of the optical path of the laser beam 6 that has passed through the window portion 14 on the lower surface side of the upper wall portion 11 of the dust collector 30. In addition, it is preferable to include a dustproof chamber 20 whose lower end is opened so that the laser beam 6 can pass through, and an air feeding means for supplying air to make the inside of the dustproof chamber 20 positive.

  The dustproof chamber 20 and the air feeding means may be anything, and for example, the configuration shown in FIG. 1 can be used. That is, the dust-proof chamber 20 is disposed on the lower side of the upper wall portion 11 of the dust collector 30 by a cover member that surrounds the side of the optical path of the laser light 6 so as to airtightly cover the range including the window portion 14. Has been. The dustproof chamber 20 may be directly connected to the window portion 14, or another member may be disposed therebetween. An opening 21 is formed at the lower end of the dustproof chamber 20 so that the laser beam 6 can pass therethrough. Further, in order to keep the inside of the dustproof chamber 20 at a positive pressure, an air feed hole 22 is provided in the dustproof chamber 20 as an air feed means. By holding the inside of the dustproof chamber 20 at a positive pressure, it is possible to prevent the dust 42 collected in the dust collector 30 from adhering to the window portion 14 and to prevent the transmittance of the laser light 6 from being lowered. can do. Thereby, it is possible to prevent the processing energy from changing during laser processing, and to perform highly accurate laser processing stably.

  The air inlet hole 22 may be provided in any position as long as it is in the dustproof chamber 20, and a plurality of air inlet holes 22 may be provided. In order to push out the air in the dustproof chamber 20 from the upper part and make a stable positive pressure state, it is preferable to provide an air inlet hole 22 in the upper part of the dustproof chamber 20. The dustproof chamber 20 may have any shape as long as it surrounds the side of the optical path of the laser beam 6. For example, the dustproof chamber 20 may have a circular cross-sectional shape, a cross-sectional elliptical shape, or a cylindrical shape with a rectangular cross-section. In order to prevent dust from entering the dustproof chamber 20, it is preferable to have a cone shape that gradually decreases in diameter toward the lower end.

  In the dust collecting and discharging apparatus of the present invention, the distance L from the bottom 13 of the dust collector 30 to the surface position of the sheet material 41 is not particularly limited, but if the distance L is too large, the dust 42 is difficult to be sucked from the suction port 16. Therefore, it is generally 1 to 10 mm, preferably 1 to 3 mm. If the distance L is 1 to 3 mm, the machining space in the vicinity of the suction port 16 is hardly affected by the external air flow, so that dust can be eliminated with higher accuracy.

  The dust collector for laser processing according to the present invention collects during the suction / discharge operation from the suction of the bottom 13 of the dust collector 30 to the suction port 16 and the discharge of the side wall 15 from the discharge port 15 by the suction / discharge means. It is preferable to provide eddy current generating means for generating a vortex flow in the dust body 30 and discharging the air flow including the dust 42 from the discharge port 15 as a rising vortex flow. By generating eddy currents in the dust collector 30, when the dust collector 30 moves at high speed, an anisotropy is caused in the air flow by suction depending on the moving direction, and variations in dust collection performance are prevented. be able to. Thereby, dust can be eliminated with higher accuracy.

  Any means may be used as the eddy current generating means. A vortex can be generated by adjusting the arrangement specifications of the air ejection holes 17 used for the air curtain forming means and / or the exhaust port 15 used for the suction / exhaust means, and another air feed for generating the vortex A hole or the like can also be provided. It is preferable to adjust the arrangement specifications of the air ejection holes 17 and / or the exhaust ports 15 in that another member is unnecessary.

  FIG. 2 is a view for explaining an example of a preferred embodiment of the eddy current generating means of the dust collection device of the present invention, and FIG. 2 (a) is a schematic bottom view of the dust collection body 30 near the air ejection hole 17. FIG. 2B is a schematic sectional view thereof. In FIG. 2A, the air ejection holes 17 disposed around the suction port 16 provided in the bottom portion 13 of the dust collector 30 are shown from the lower surface side of the dust collector 30, and the air ejection holes 17 are arranged. In order to indicate the installation direction, the internal shape of the air ejection hole 17 is indicated by a broken line. Moreover, in FIG.2 (b), it is a cross section at the time of cut | disconnecting by the line E of Fig.2 (a), and the air ejection hole 17 in the inside of the bottom part 13 of the back | inner side is shown with the broken line.

  As shown in the drawing, the plurality of air ejection holes 17 are arranged to form a circular shape C, and each air ejection hole 17 (12 holes in FIG. 2A) has a tangential direction D when the circular shape C is drawn. Are arranged at an angle with a predetermined angle R in substantially the same direction. Thereby, the air ejected from the air ejection holes 17 is reflected by the sheet material 41 at an angle in the circumferential direction of the circular shape C and is sucked into the dust collector 30 from the suction port 16. Since the sucked airflow has an angle in the circumferential direction, it becomes a vortex rising airflow in the dust collector 30 and is discharged from the discharge port 15. The angle R is not particularly limited as long as it forms a stable air curtain and is adjusted so that the airflow sucked into the dust collector 30 becomes a vortex rising airflow. Generally, it is 0 to 45 degrees, preferably 10 to 20 degrees.

  FIG. 3 is a view for explaining another example of the preferred embodiment of the eddy current generating means of the dust collecting apparatus of the present invention. FIG. 3 (a) is a schematic crossing at the position of the exhaust port 15 of the dust collecting body 30. FIG. 3B is a schematic perspective view of the dust collector 30 cut in the vertical direction in order to show the inside of the dust collector 30. FIG. 3A and 3B, the side wall 12 of the dust collector 30 is formed in a cylindrical shape. The side wall portion 12 is provided with two exhaust ports 15 as suction / exhaust means, and each exhaust port 15 is disposed in the tangential F direction of the side wall portion 12 of the dust collector 30. That is, the discharge direction of the airflow discharged from the exhaust port 15 is set to the tangent F direction of the side wall portion 12. Thereby, since the air flow including the dust 42 sucked from the suction port 16 flows along the side wall portion 12 of the dust collector 30, a vortex rising air flow is formed and exhausted from the exhaust port 15. Although the number of the exhaust ports 15 may be one, it is preferable that a plurality of air outlets 15 are provided on the side wall portion 12 so that the air is exhausted efficiently. It is preferable that the discharge ports 15 are arranged at equal intervals so that a vortex flow is generated in a balanced manner. If many of the dust collectors 30 are disposed, the weight of the dust collector 30 increases. Therefore, it is particularly preferable to dispose two dust collectors 30 as shown in FIG.

When the dust collector for laser processing according to the present invention is used, the air ejection amount from the air inlet hole and the air ejection hole, and the exhaust amount from the exhaust port as the suction exhaust means, the optical path of the laser beam is secured, and the sheet There is no particular limitation as long as it is adjusted so that dust generated at a processing point on the material can be efficiently removed. Air feed Iriryou the air feed-in hole 22 as the air fed means, generally 0.01~1m ³ / min, preferably 0.1-0.5 M ³ / min, air injection hole as an air curtain forming means air ejection quantity of 17 is generally 0.01~1m ³ / min, preferably 0.1-0.5 M ³ / min, exhaust amount from the exhaust port 15 is typically 1 to 5 m ³ / min, preferably Is 0.2 to 1 m ³ / min. A suitable pressure balance during use of the dust collection device of the present invention will be described below.

  FIG. 4 is a schematic cross-sectional view for explaining a suitable pressure balance in and around the dust collector when the dust collector for laser processing of the present invention is used. Pa, Pg, Pc / i, Pc / o, Pc / u, Pb, and Pv respectively indicate pressures at points indicated by black circles at the ends of the indicator lines. That is, Pa is the atmospheric pressure, Pg is the pressure in the gap between the dust collector 30 and the sheet material 41, and Pc / i is the pressure at the center of the processing space surrounded by the outer peripheral wall 19 (perpendicular from the vicinity of the center point of the suction port 16). Pc / o is the pressure outside the machining space (near the outer peripheral wall 19), Pc / u is the pressure above the machining space in the dust collector 30, and Pb is the pressure inside the dustproof chamber 20. , Pv indicates the pressure in the exhaust port 15.

  When the dust collector for laser processing of the present invention is used, that is, when the dust collector 30 is moving in the horizontal direction over the sheet material 41, the pressure at each point is expressed by the following formulas (I) and (II). It is preferable that both of these relationships are established.

P _a <P _g <P _{c / i} <P _{c / o} (I)
P _v <P _{c / u} <P _b <P _{c / i} (II)

  With such a pressure balance, the dust generated in the processing space is sucked into the dust collector 30 without being affected by the external air, and the sucked dust is put in the dustproof chamber 20. The air can be discharged from the exhaust port without entering.

  In addition, this invention is not limited to the structure and Example of said embodiment, A various deformation | transformation is possible within the range of the summary of invention.

  By using the dust collector for laser processing of the present invention, it is a case where a large sheet material is laser processed, and even if the moving speed of the optical system is increased, dust can be eliminated with high accuracy, Because we can do high-precision fine processing. Productivity such as high quality optical filters for PDP can be improved.

5 Condensing lens 6 Laser beam 7 Processing location 11 Upper wall portion 12 Side wall portion 13 Bottom portion 14 Window portion 15 Exhaust port 16 Suction port 17 Air outlet hole 18 Air curtain 19 Outer wall 20 Dustproof chamber 21 Opening portion 22 Air inlet hole 30 Dust collector 40 Table 41 Sheet material 42 Dust

Claims (10)

In a dust collector that is installed in a processing work space of a laser processing apparatus that processes a flat workpiece by laser light irradiation and prevents dust scattering caused by the processing and discharges dust.
A side wall portion surrounding the laser processing work location, an upper wall portion having a window portion that allows the upper opening of the side wall portion to be hermetically shielded and allows the laser beam to pass therethrough, and a position facing the processing location of the flat plate workpiece A dust collector having a bottom with an opening in
Suction and discharge means for sucking the dust from an opening provided at the bottom of the dust collector and discharging the dust from a discharge port provided on a side wall of the dust collector;
Air curtain forming means for ejecting air from the periphery of the opening at the bottom of the dust collector, and forming an air curtain between the bottom and the flat workpiece;
An outer peripheral wall surrounding the periphery of the air curtain;
A dust collecting apparatus for laser processing characterized by comprising: The air curtain forming means includes
A plurality of air ejection holes arranged at predetermined intervals around the bottom opening of the dust collector, and the air curtain is formed by injecting air from the air ejection holes. The dust collection apparatus for laser processing according to claim 1. An inner dust-proof chamber that surrounds the side of the optical path of the laser beam that has passed through the window and is opened at the lower end so that the laser beam passes, on the lower surface of the upper wall of the dust collector;
Air feeding means for supplying air into the dustproof chamber in order to make the dustproof chamber have a positive pressure;
The dust collecting apparatus for laser processing according to claim 1 or 2, characterized by comprising:   The distance from the bottom part of the said dust collector to the surface position of the said flat workpiece is 1-3 mm, The dust collection apparatus for laser processing of any one of Claims 1-3.   The dust collector is provided with eddy current generating means for generating a vortex flow in the dust collector during the suction operation of the suction / discharge means and discharging the dust from the discharge port as a vortex air flow. The dust collection apparatus for laser processing according to any one of claims 1 to 4. The plurality of air ejection holes are arranged to form a substantially circular shape,
The vortex generating means is
6. The dust collector for laser processing according to claim 5, wherein each of the plurality of air ejection holes is formed at a predetermined angle in substantially the same direction of the substantially circular tangential direction. The side wall portion of the dust collector is formed in a substantially cylindrical shape,
The vortex generating means is
6. The apparatus according to claim 5, wherein the suction direction of the dust from the discharge port of the dust collector is set to be a tangential direction of the side wall of the dust collector. 6. A dust collector for laser processing according to item 6.   The discharge port of the dust collector is provided at a plurality of locations on the side wall, and the dust is discharged from the plurality of discharge ports. Dust collector for laser processing.   The dust collection apparatus for laser processing according to any one of claims 3 to 8, wherein the dustproof chamber has a cone shape that gradually decreases in diameter toward a lower end.   The dust collection apparatus for laser processing according to any one of claims 1 to 9, wherein a material of the window portion is zinc selenide.

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